Photosensitive epilepsy

Transcription

1 Photosensitive epilepsy Epilepsy Helpline:

2 Epilepsy Action aims to improve the quality of life and promote the interests of people living with epilepsy. Our work... We provide information to anyone with an interest in epilepsy. We improve the understanding of epilepsy in schools and raise educational standards. We work to give people with epilepsy a fair chance of finding and keeping a job. We raise standards of care through contact with doctors, nurses, social workers, government and other organisations. We promote equality of access to quality care. Epilepsy Action has local branches in most parts of the UK. Each branch offers support to local people and raises money to help ensure our work can continue. Your support We hope you find this booklet helpful. As a charity, we rely on donations to provide our advice and information. If you would like to make a donation, here are some ways you can do this. Visit epilepsy.org.uk/donate Text ACT NOW to (This will cost you 5 plus your usual cost of sending a text. Epilepsy Action will receive 5.) Send a cheque payable to Epilepsy Action. Did you know you can also become a member of Epilepsy Action from as little as 1 a month? epilepsy.org.uk/info/photosensitive-epilepsy 2 Photosensitive epilepsy

3 Contents Introduction 5 About photosensitive epilepsy 5 About hertz (Hz) 6 Diagnosing photosensitive epilepsy 6 Ways to reduce the risk of seizures if you have photosensitive epilepsy 7 Some possible seizure triggers for people with photosensitive epilepsy 8 Useful information and contacts 16 Photosensitive epilepsy 3

4

5 Introduction The aim of this booklet is to tell you what photosensitive epilepsy is, who it affects and what might trigger a seizure if you have photosensitive epilepsy. There are also suggestions for reducing the risk of having a seizure. About photosensitive epilepsy Photosensitive epilepsy is a type of epilepsy, in which all, or almost all, seizures are triggered by flashing or flickering light. Both natural and artificial light may trigger seizures. Some patterns, like stripes or checks, can also trigger seizures for some people with photosensitive epilepsy. Various types of seizure can be triggered by flashing or flickering light. These include tonic-clonic, absence, myoclonic and focal seizures. The most common is a tonic-clonic seizure. The seizure(s) will usually happen at the time of, or shortly after, looking at the trigger. Around three in every 100 people with epilepsy have photosensitive epilepsy. It usually begins before the age of 20, most commonly between the ages of seven and 19. Photosensitive epilepsy affects more girls than boys. Epilepsy Action has more information about epileptic seizures. Photosensitive epilepsy 5

6 About hertz (Hz) The word hertz (Hz) refers to how often something happens in a second. For example, it can mean the number of times something flashes or flickers in one second. It can also mean the number of times the scanning lines on televisions and computer monitors refresh themselves in one second. Most people with photosensitive epilepsy are sensitive to Hz. Some people may be sensitive to rates as low as 3 Hz and as high as 60 Hz. Diagnosing photosensitive epilepsy If you have an epileptic seizure when looking at flashing or flickering lights or certain patterns, this is a sign that you may have photosensitive epilepsy. Your doctor may ask you to have an electroencephalogram (EEG) test. This test records the electrical signals from your brain on an EEG machine. During the test, you will be asked to look at some flashing lights. If doing this changes the electrical signals in your brain, it may indicate that you have photosensitive epilepsy. The person doing the test will usually try to stop the test before you actually have a seizure. However, there is a small risk that you will have a seizure when the test is done. Epilepsy Action has more information about EEG tests and diagnosing epilepsy. 6 Photosensitive epilepsy

7 Ways to reduce the risk of seizures if you have photosensitive epilepsy Avoid looking at anything that you know may trigger a seizure. Avoid things that can increase your risk of having a seizure. These can include feeling tired or stressed, not having enough sleep and drinking alcohol. If you take epilepsy medicine, always take it as prescribed by your doctor. If you look at something that might trigger a seizure, don t close your eyes. This could increase your risk of having a seizure. Instead, immediately cover one eye with the palm of your hand and turn away from the trigger. This reduces the number of brain cells that are stimulated and reduces the risk of a seizure happening. Photosensitive epilepsy 7

8 Some possible seizure triggers for people with photosensitive epilepsy Ceiling fans Light seen through a fast-rotating ceiling fan may trigger a seizure. Using a slow-rotating fan would reduce this risk. Cinema films Watching films, including 3D films, at the cinema doesn t pose a risk in itself. However, some films contain images such as flashing or flickering lights, which could trigger a seizure. In the UK, the British Board of Film Classification states that it is up to the film makers and distributors to identify works in which there may be problems with flashing lights. They should then make sure that, if necessary, warnings are given to viewers about this. However, there is no guarantee that this will always happen. Computer and television screens It is unusual for modern computer and television screens to trigger seizures. But it could happen, depending on the screen or the images that you are looking at. Types of screen There are different types of screen which can be used with a computer or when watching television. These include cathode ray tube screens, liquid crystal screens and plasma screens. 8 Photosensitive epilepsy

9 Cathode ray tube screens Cathode ray tube (CRT) screens use tubes to create a picture. They are the older style of screen and are large and bulky. They are prone to flickering. Modern CRT screens have a refresh rate of 100 times each second (100Hz). These are unlikely to trigger a seizure, unless they are faulty. Older CRT screens may refresh the picture at a rate which could trigger a seizure, especially if you sit near to the screen. Liquid crystal screens Liquid crystal display (LCD), lightemitting diode (LED) and thin-film transistor (TFT-LCD) screens all use liquid crystals to create a picture. They are all thin and have a flat screen. Liquid crystal screens don t flicker and are far less likely to trigger a seizure than CRT screens. However, the risk of having a seizure is not removed entirely, because they are brighter and have more contrasting colours than CRT screens. Contrasting colours increase the risk of seizures. Plasma screens Plasma display panel (PDP) screens use tiny gas plasma cells to create a picture. They are thin and have a flat screen. Plasma screens don t flicker and are far less likely to trigger a seizure than CRT screens. The risk of having a seizure is not removed entirely, because plasma screens are brighter and have more contrasting colours than both CRT and liquid crystal screens. Contrasting colours increase the risk of seizures. Photosensitive epilepsy 9

10 Choosing a screen If you have photosensitive epilepsy, the current advice is to use an LCD screen. This is the type that carries the least risk of triggering a seizure. Images on computer and television screens The content you look at on a computer or television could trigger seizures if it has any of the following. Flashing or flickering lights For example, when there are a lot of press photographers on television, all using a camera flash at the same time. Rapidly changing images For example, these may appear when you are playing on a games console. Contrasting or moving patterns For example, these may appear when you are watching video clips on a computer. 10 Photosensitive epilepsy

11 In the UK, there are guidelines for TV broadcasters to restrict the use of images that may cause a problem for people with photosensitive epilepsy. They should also give a warning if a programme has images that could trigger a seizure. However, there is no guarantee that a warning will always be given. General safety suggestions for watching television or using a computer Make sure that the room is well lit. Have a lamp lit close to the screen. If possible, use a liquid crystal or plasma screen and reduce the brightness setting. If you use a CRT screen, make sure that the refresh rate is set to greater than 70Hz. Also make sure that the screen is in good working order. Consider covering one eye with something that won t let light through, such as an eye patch. This will reduce the number of brain cells that are stimulated by any flashing or flickering. For most people with photosensitive epilepsy, this will minimise the risk of having a seizure. If you have any discomfort, such as dizziness, blurred vision, loss of awareness or muscle twitching, stop looking at the screen immediately. Take frequent breaks for rest and food. Photosensitive epilepsy 11

12 Safety suggestions specific to watching television Sit or stand at a distance of at least 2.5 metres (8 feet) from the television. Use the remote control wherever possible from a safe distance to adjust the television or to change channels. If you have to go near the television, cover one of your eyes with the palm of your hand. 3D television 3D images do not have a higher risk of triggering a seizure than 2D images, as long as you follow these safety guidelines. Remove 3D glasses before you stop watching something in 3D. This is because the glasses flicker for a few seconds when 3D is turned off. This flickering could trigger a seizure. If you are using an active shutter 3D system, the television should not be placed near a window. When it is daylight, the active shutter glasses produce a flicker in the window. This could trigger a seizure. Interactive whiteboards Looking at an interactive whiteboard is not likely to trigger a seizure, unless the material shown contains flashing or flickering lights, or contrasting patterns. Lighting Fluorescent strip lights and light bulbs may trigger a seizure if they flicker because they are faulty. Otherwise, they should not cause you a problem. 12 Photosensitive epilepsy

13 Flashing Christmas tree lights Flashing Christmas tree lights that are put up by public organisations in the UK, such as local councils, have to comply with health and safety regulations. They should not flash at a rate that could trigger seizures in most people with photosensitive epilepsy. Christmas tree lights that are sold to the public do not have to comply with health and safety regulations. They could flash at any rate, so there is the possibility that they could cause you to have a seizure. Flashing novelty badges Novelty badges do not have to comply with health and safety regulations, so they could flash at any rate. There is the possibility that these could cause you to have a seizure. Red flashing bicycle lights Red flashing bicycle lights (light emitting diodes, or LEDS) have triggered seizures in a small number of people. This has happened when they were very close to the lights, setting them up. Photosensitive epilepsy 13

14 Strobe lights You may come across strobe lights in places like night clubs, discos and theme parks. In the UK, the flash rate of strobe lights is restricted to a maximum of four flashes a second by the Health and Safety Executive. This rate is considered to be safe for most people. However, some people with photosensitive epilepsy may still find strobe lights could trigger a seizure. Patterns Some high contrast or moving patterns can trigger seizures in some people with photosensitive epilepsy. Here are some examples. Black and white stripes Some patterned materials and wallpapers Large areas of floor and ceiling tiles with high contrast lines Looking down a moving escalator 14 Photosensitive epilepsy

15 Sunlight Being in sunlight is unlikely to trigger a seizure if you have photosensitive epilepsy. However, looking directly at certain patterns connected with sunlight could trigger a seizure. Here are some examples. Sunlight through slatted blinds Sunlight through trees, viewed from a moving vehicle Sunlight reflected off moving water Sunlight through moving leaves Sunlight through railings, as you move past them Sun beds Sun beds may trigger a seizure if the tubes flicker because they are faulty. Otherwise, they should not cause you a problem. Wind turbines In the UK, the flicker frequency of wind turbines on wind farms should be limited to 3 Hz. This flicker rate is unlikely to trigger a seizure. Wind turbines that are not on wind farms are not subject to the same planning regulations as wind farms. If a turbine is in the wrong position in relation to the sun, it could create a strobe effect. This could trigger a seizure for some people with photosensitive epilepsy. If you live in the UK and have concerns about a planned or existing wind farm, you may wish to contact the British Wind Energy Association (BWEA), who can provide contact details of specific wind farm operators. Photosensitive epilepsy 15

16 Useful information and contacts British Wind Energy Association (BWEA) Greencoat House, Francis Street, London SW1P 1DH Telephone: ; Health and Safety Executive Helpline: Their guide Disco lights and flicker sensitive epilepsy can be found at: Office of Communications (Ofcom) Riverside House, 2a Southwark Bridge Road, London SE1 9HA Telephone: ; 16 Photosensitive epilepsy

17 About this publication This booklet is written by Epilepsy Action s advice and information team, with guidance and input from people living with epilepsy and medical experts. If you would like to know where our information is from, or there is anything you would like to say about the booklet, please contact us. Epilepsy Action makes every effort to ensure the accuracy of information in its publications but cannot be held liable for any actions taken based on this information. Date: March 2012; Due for review: March 2015; Code: B Acknowledgements Epilepsy Action would like to thank Professor G F A Harding, Emeritus Professor of Clinical Neurophysiology, Aston University and also Professor Stefano Seri, Professor of Clinical Neurophysiology at Aston University and Consultant at the Birmingham Children s Hopsital NHS Foundation Trust for their contribution to this information. Photosensitive epilepsy 17

18 First aid for tonic-clonic seizures The person goes stiff, loses consciousness and falls to the floor. Do... Protect the person from injury (remove harmful objects from nearby) Cushion their head Aid breathing by gently placing the person in the recovery position when the seizure has finished (see the pictures) Stay with them until recovery is complete Be calmly reassuring 1 2 Don t... Restrain the person s movements 3 Put anything in their mouth Try to move them unless they are in danger Give them anything to eat or drink until they are fully recovered Attempt to bring them round Call 999 for an ambulance if... You know it is the person s first seizure The seizure continues for more than five minutes One seizure follows another without the person regaining consciousness between seizures The person is injured You believe the person needs urgent medical attention 18

19 First aid for focal (partial) seizures The person is not aware of their surroundings or of what they are doing. They may pluck at their clothes, smack their lips, swallow repeatedly or wander around. Do... Guide the person away from danger Stay with the person until recovery is complete Be calmly reassuring Explain anything that they may have missed Don t... Restrain the person Act in a way that could frighten them, such as making abrupt movements or shouting at them Assume the person is aware of what is happening, or what has happened Give them anything to eat or drink until they are fully recovered Attempt to bring them round Call 999 for an ambulance if... You know it is the person s first seizure The seizure continues for more than five minutes The person is injured You believe the person needs urgent medical attention 19

20 Further information If you have any questions about epilepsy, please contact the Epilepsy Helpline. Epilepsy Action has a wide range of publications about many different aspects of epilepsy. Information is available in the following formats: booklets, fact sheets, posters, books, videos and DVDs. Information is also available in large text. Please contact Epilepsy Action to request your free information catalogue. Epilepsy Action s support services Local meetings: a number of local branches offer support across England, Northern Ireland and Wales. forum4e: our online community is for people with epilepsy and carers of people with epilepsy. For people aged 16 years or over. Join at Epilepsy awareness: Epilepsy Action has a number of trained volunteers who deliver epilepsy awareness sessions to any organisation that would like to learn more about epilepsy. The volunteers are able to offer a comprehensive introduction to epilepsy to a range of audiences. If you would like more information about any of these services, please contact Epilepsy Action. Contact details are at the back of this booklet. 20 Photosensitive epilepsy

21 Photosensitive epilepsy Please complete this form to tell us what you think of this publication. How useful have you found this publication? Very useful Useful Quite useful Not at all useful Is the language clear and easy to understand? Very clear and easy to understand Clear and easy to understand Quite clear and easy to understand Not at all clear or easy to understand Does this publication cover all you want to know about the topic? Completely Mostly Not quite Not at all What do you think of the design and general layout of this publication? Excellent Good OK Poor Please let us have your comments: B Date: Please return the completed form to: Epilepsy Services, Epilepsy Action, FREEPOST LS0995, Leeds LS19 7YY Photosensitive epilepsy 21

22 Epilepsy Action FREEPOST LS0995 LEEDS LS19 7YY Registered charity in England (No )

23 How to contact the Epilepsy Helpline Telephone the Epilepsy Helpline freephone Monday to Thursday 9.00 am to 4.30 pm Friday 9.00 am to 4.00 pm Our helpline staff are Text Relay trained Write to us free of charge at FREEPOST LS0995, Leeds LS19 7YY us at or visit our website: Text your enquiry to Send a Tweet About the Epilepsy Helpline The helpline is able to offer advice and information in 150 languages. We provide confidential advice and information to anyone living with epilepsy but we will not tell them what to do. We can give general medical information but cannot offer a medical diagnosis or suggest treatment. We can give general information on legal and welfare benefit issues specifically related to epilepsy. We cannot, however, take up people s cases on their behalf. Our staff are trained advisers with an extensive knowledge of epilepsy related issues. Where we cannot help directly, we will do our best to provide contact details of another service or organisation better able to help with the query. In doing this, Epilepsy Action is not making a recommendation. We welcome comments, both positive and negative, about our services. To ensure the quality of our services we may monitor calls to the helpline. Photosensitive epilepsy 23

24 B Epilepsy Helpline: freephone Copyright Epilepsy Action 2012 Epilepsy Action New Anstey House, Gate Way Drive, Yeadon, Leeds LS19 7XY tel Epilepsy Action is a working name of British Epilepsy Association. A company limited by guarantee (registered in England No ) Registered charity in England (No ) Date: March 2012; Due for review: March 2015 Environmental statement All Epilepsy Action booklets are printed on environmentally friendly, low-chlorine bleached paper. All paper used to make this booklet is from well-managed forests.